EFFECT OF PUMPKIN (Telfairia occidentalis) POD ON BIOGAS PRODUCTION FROM CO-DIGESTION OF YEAST (Saccharomyces cerevsiae) AND MAIZE COB IN BATCH REACTORS

Abstract

Anaerobic digestion (AD) is a technology widely used for treatment of organic waste for biogas production. This study was conducted in Faculty of Agriculture, University of Benin, Benin City to determine the biogas yield of blending pumpkin pod (0, 1, 2, 3 and 4g), yeast
and maize cob (2g of yeast and 2g of maize cob) by means of batch experiment at mesophilic temperature, the effect of pumpkin pod composition in biogas yield and to analyse the composition effect on the biogas component. The experiment was arranged in a completely randomized design with three replicates using a set of five batch reactors. Each digester contained fixed amount of yeast and maize cob (2g of each), but an increasing amount of pumpkin pod (0 - 4g). The digesters were labeled A, B, C, D and E respectively. The % total solid composition was calculated and the pH determined before corking. The results showed significant differences among %composition of pumpkin pod for biogas yield and methane component. Yeast, % total solid composition and retention time significantly affected the biogas yield in the five-digesters. Digester loaded with 4g of pumpkin pod produced  significantly higher volume of biogas and methane component compared with other loading rates. Increase in biogas yield for loading rate of 4g was 49.666ml for the 10 days hydraulic retention time. The retention time of 5, 6 and 7 days significantly produced the highest volume of biogas. The study showed that the blending of pumpkin pod, maize cob and yeast can be of rational inclusion in biogas production if properly harnessed.